package LeetCode._01_树;
/**
 * https://leetcode-cn.com/problems/invert-binary-tree/
 */
public class _226_翻转二叉树 {
    public class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;
        TreeNode() {}
        TreeNode(int val) { this.val = val; }
        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }

    public TreeNode invertTree(TreeNode root) {
        if(root == null) return null;

        invertTree(root.left);
        invertTree(root.right);

        TreeNode tmp = root.left;
        root.left = root.right;
        root.right  = tmp;

        return root;
    }
}
    

